A Novel 65 nm Radiation Tolerant Flash Configuration Cell Used in RTG4 Field Programmable Gate Array

The newly introduced radiation-tolerant flash-based FPGA, RTG4, uses a novel configuration cell design composed of a NMOS switch controlled by a totem pole p-channel flash and n-channel flash construction. Its radiation tolerance is far superior to that in the present available Flash-based FPGA. This paper describes the radiation hardening by design (RHBD) process for the new flash-based configuration cell. A subtle and unique retention issue was found and resolved through studying physical mechanisms and conducting experiments.